1: Dog of old opium-eater in novel (9,6)
2: British Petroleum dispute (5)
3: So sad coming back, Pops (5)
4: A bit of the English course may cause embarrassing situations (7)
5: Bring bad luck when you allow teasers the stage! (3,3,7,2)
7: Come to Korea - Chinese part (5)
9: Bore stopped outside ancient city (7)
11: The portrayal of things as they are in Mailer's novel (7)
13: Drongo lacks even a pet (3)
14: Solo, the pilot rises? No way (3)
16: State goddess gets in first (7)
18: To escape with lover from Warsaw, man climbs last section of fence (5)
20: DVD possibly missing model of natural filter (5)
21: A small rig is something worth having (5)